FIG. 1 shows a simplified perspective view of a conventional flip chip package 100. FIG. 1A shows a cross-sectional view of the package of FIG. 1 taken along line 1A-1A′.
This conventional flip chip package 100 comprises die 102 enclosed within plastic package body 104. Electrical contacts 106 on the top surface of die 102 are in electrical communication with the leads 108 projecting from the package body, through electrically conducting solder connections 110.
As indicated in FIG. 1A, it is required that the leads 108 maintain a minimum height Z over the die. However, as shown FIG. 1B, during the step of attaching the leads to the die, heating of the solder connection may result in solder reflow, causing the shape of the solder connection to deform and possibly resulting in the height of the lead Z′ being less than the required height Z.
Accordingly, there is a need in the art for improved techniques for fabricating a flip chip die which avoids the problems resulting from deformation in a solder contact resulting from reflow.